Quarks observed to interact via minuscule 'weak lightsabers'
Atlas Experiment
As light beams of photons from torches or lasers unaffectedly penetrate each other, electromagnetic lightsabers will forever stay science fiction. One quark in each of two colliding protons has to radiate a W or a Z boson. This continues the experiment’s long journey to scrutinise the VBS process: using 8 TeV data from 2012, ATLAS had obtained the first evidence for the W±W± → W±W± process with 18 candidate events. Such a yield would occur with a probability of less than 1:3000 as a pure statistical fluctuation. Besides the decay products of the scattered W or Z bosons, the signature of the process are two high-energetic particle jets originating from the two quarks that initially radiated the W or Z. ATLAS has also combined 2015 and 2016 data to establish the scattering of W±Z → W±Z with a statistical significance of 5.6 σ above background.